Sulfonaphthylamino thiosulfato compounds and their preparation



:naphthyl,

United States Patent 3,496,207 SULFONAPHTHYLAMINO THIOSULFATO COM- POUNDS AND THEIR PREPARATION Frederick E. Barwick III and Gordon A. Geselbracht,

Charlotte, N .C., assignors to Martin Marietta Corporation, a corporation of Maryland No Drawing. Filed Sept. 25, 1967, Ser. No. 670,440 Int. Cl. C07c 143/04, 143/30 US. Cl. 260453 7 Claims ABSTRACT OF THE DISCLOSURE sium salt form of said radicals; X is phenylene, ethylene,

propylene,

(EH2- in which the -CH is bonded to the SSO Z, chlorophenylene in which the Cl is ortho to the SSO Z, methoxyphenylene in which the methoxy is meta to the SSO Z,

SO NH-CH O 2 v.

in which a methylene is bonded to the -SSO Z, or

S zNH \C /2 in which a methylene is bonded to the -SSO Z; and Z is H, Na or K. Also disclosed is a method for making RNHX-SSO Z comprising heating an aqueous composition comprising approximately equimolar proportions of H N-XSSO Na and a sulfonic acid or salt thereof selected from the group consisting of 6- or 7- amino-1-naphthol-3-sulfonic acid, 8-amino-1-naphthol-5- sulfonic acid, 6- or 7-amino-1,B-naphthalenedisulfonic acid, 8-amino-1-naphthol-4,6- or 3,5- or 5,7-disulfonic,

acid, 6-amin0-lor 2-naphthalenesulfonic acid, 2-naphthol-7- or -8-sulfonic'a'cid, 4,5-dihydroxy-1-naphthalenevsulfonic acid, 4-amino-1-naphthalenesulfonic acid, 1,6-dihydroxy-3-naphthalenesulfonic acid 'and the sodium or potassium salt form of said acids, 3.5-7 molecular pro- 025" C.; and collecting the resulting precipitated product which is in acid form, and which may be converted to the corresponding sodium or potassium salt form with aqueous NaOH, Na CO KOH or K 00 V The present invention relates to thiosulfato compounds and method for making same.

The compounds of the present invention are particularly' characterized in that they have the formula R-NHXSSO Z, wherein R is 8-hydroXy-6-su1fo-2- 5-hydroxy-7-sulfo-2-naphthyl, 8-hydroxy-4- sulfo-l-naphthyl, 6,8-disulfo-2-naphthyl, 5,7-disulfo-2- naphthyl, 8-amino-4,5-disulfo-l-naphthyl, 6-sulfo-2-naph- 3,496,207 Patented Feb. 17, 1970 thyl, 8-sulfo-2-naphthyl, 5-sulfo-2-naphthyl, S-hydroxy- 4,6-disulfo-1-naphthyl, 8-amino-5,7-disulfo-l-naphthyl, 7- sulfo-2 naphthyl, 4-sulfo-l-naphthyl, or the sodium or potassium salt form of said naphthyl radicals; X is pher1y1 ene, ethylene, propylene,

(IJH2 in which the CH is bonded to SSO Z, chlorophenylene in which the Cl is ortho to the 4SO Z, methoxyphenylene in which the methoxy is meta to the in which a methylene is bonded to the SSO Z, or

in which a methylene is bonded to the SSO Z; and Z is H, Na or K.

Generally speaking, the method of the present invention is a process for making a compound of the formula R NH--XSSO H comprising the steps of heating for 12-60 hours at 60-105 C. and pH 6.2 an aqueous composition containing approximately equimolar proportions of H NXSSO Na and a member selected from the group consisting of 7-amino-1-naphthol-3-sulfonic acid, 6-amino-1-naphthol-3-sulfonic acid, 8-amino-1-naphthol- S-sulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid, 6-arnino-1,3-naphthalenedisulfonic acid, 8-a'mino-1-naphthol-4,6-disulfonic acid, 6-amino-2-naphthalenesu1fonic acid, Z-naphthol-S-sulfonic acid, 6-amino-1-naphthalenesulfonic acid, 4,5-dihydroXy-1-naphthalenesulfonic acid, S-amino-1-naphthol-3,5-disulfonic acid, 8-amino-1-naphthol-5,7-disulfonic acid, 2-naphthol-7-sulfonic acid, 4- amino-l-naphthalenesulfonic acid, 1,6-dihydroXy-3-naphthalenesulfonic acid, and the sodium or potassium salt form of said acids, 3.5-7 molecular proportions NaHSO per mole of H NXSSO Na, and about 0.11 molecular proportions Na CO per mole of NaHSO or about in which the CH is bonded to the divalent S atom of the thiosulfato radical, chlorophenylene in which the Cl is ortho to the divalent S atom of the thiosulfato radical, methoxyphenylene in which the methoxy is meta to the divalent S atom of the thiosulfato radical,

in which a methylene is bonded to the divalent S atom of the thiosulfato radical, or

f v SOzNH \CH2/2 in which a methylene is bonded to the divalent S atom of the thiosulfato radical.

At this stage, the naphthyl radicals and thiosulfuric acid group of the R -NHXSSO H will be in their acid form; the R -NHXSSO H may be converted to the corresponding sodium salt form by stirring the R NH--XSSO H in an excess of 520% aqueous NaOH or Na CO at about 25 C. for about 15 minutes, following which the compound may be caused to precipitate by addition of 20% aqueous NaCl and recovered by filtration. Likewise, the R NH-X-SSO H in acid form may be converted to its corresponding 'It will also be understood that inthe foregoing nomenclature system sulfo designates ,-SO H, and thiosulfato radical designates SSO which may also be Written the left S being the divalent S atom of the radical.

The compounds of the present invention are particularly suitable as intermediates for use in making valuable water-soluble monoazo dyes. For example, equimolar amounts of the compounds of the present invention may be coupled in the conventional manner, in acid or alkaline aqueous media, at 010 C. with a solution of a diazotized amine (azoic base), such as the primary amines shown at Lubs, The Chemistry of Synthetic Dyes & Pigments, pp. 196-207 (1955 ed.). The resulting dyes may be applied to cotton or regenerated cellulose fabric by the dyeing method described in Belgian Patent No. 681,524.

It is surprising and unexpected that the compounds of the present invention may be prepared, because one with skill in the art would expect the notoriously labile thiosulfate group to hydrolyze under the present reaction conditions. It is particularly surprising that the compounds of the present invention are useful as dye inter mediates in making thiosulfate dyes fast to wet treatments, as the thiosulfate group promotes solubility in water, and the present intermediates have, in addition to a thiosulfate group, one or two sulfonic acid groups, which sulfonic acid groups are known to promote strongly solubility in water. Excessive numbers of water solubilizing groups on a dye molecule are customarily believed to render the dye non-fast to 'wet treatments and washing, and to render the dye tinctorially weak. It is therefore surprising that dyes made from the persent intermediates have good wash fastness. Moreover, many dyes made from the intermediates of the present invention have surprisingly strong tinctorial power.

The present invention is of particular value in contributing to greater flexibility in the thiosulfate dye making art. For example, it has been known in the prior art to couple one or two moles of diazotized aminophenylthiosulfates with a mole of a naphthol to make thiosulfate dyes (Canadian Patent No. 754,555, issued Mar. 14, 1967). However, in that case the'diazo coupling component was necessarily restricted to aminophenylthiosulfates. One advantage of the present invention is that one preparing thiosulfate dyes may now choose any desired diazo coupling component for coupling with the intermediates of the present invention, unlimited by whether or not the diazo contains a thiosulfate group; accordingly a broad range of diazo compounds, and those known to have good fastness properties, may now be employed.

The process of the present invention readily lends itself to commercial adaptation, in that the materials are easy to handle, simple and inexpensive plant equipment may be used, and there are no difficult separation steps.

The following is a more detailed description of the present invention, and all parts herein are by weight unless otherwise specified.

If desired, R NHXSSO H, wherein -R and X are as above defined, may be prepared by mixing together in any order approximately equimolar proportions of H N-XSSO Na wherein X is as above defined, and an acid or salt thereof selected from the group consisting of 7-amino-l-naphthol-S-sulfonic acid, 6-amino-1-naphthol-3-sulfonic acid, 8-amino-l-naphthol-S-sulfonic acid, 7-amino-1,3-naphthalenedisulfonic acids, 6-amino-l,3-naphthalenedisulfonic acid, 8-amino-1-naphthol-4,6-disulfonic acid, G-amino-2-naphthalenesulfonic acid, 2-naphthol-8-sulfonic acid, d-amino-l-naphthalenesulfonic acid,

' 4,5 -dihydroxy-l-naphthalenesulfonic acid,

S-amino-l-naphthol-3,5-disulfonic acid, S-amino-l-naphthol-5,7-disulfonic acid,

"2-naphthol-7-sulfonic acid,

4-amino-1-naphtha1enesulfonic acid, 1,6-dihydroxy-3-naphthalenesulfonic acid,

used, about 0.11 molecular proportions Na CO per molecular proportion of NaHSO used or about 0.22 molecular proportions NaOH per molecular proportion of NaHSO used, and enough H O to dissolve the mixture when subsequently heated; heating 12-60 hours at 60 C. and pH 6.2; cooling to 0-25 (3.; adding a nonoxidizing mineral acid until the pH reaches about 3, while maintaining 025 C.; evacuating substantially all S0 gas at 025 (3.; and collecting the resulting precipitated product.

However, for ease of materials handling, it is preferred to conduct the process as follows.

Warm water, at about 3050 C., may be charged into a vessel. Enough water is employed so that the reactants will dissolve when subsequently heated, and usually 2-4 parts water for each part H NX-SSO Na to be subsequently employed will be suflicient.

Mix into the warm water 3.5-7 molecular proportions NaHSO for each molecular proportion to be subsequently used.

Add thereto gradually during about'30 minutes, while stirring, either about 0.11 molecular proportions Na CO per molecular proportions of NaHSO previously used or about 0.22 molecular proportions NaOH per molecular proportion of NaHSO previously used, to provide a composition buttered at pH 6.2. Adjust temperature to about 50 C.

Add one molecular proportion of a member selected from the group consisting of 7-amino-1-naphthol-3-sulfonic acid, 6-amino-1-naphthol-3-sulfom'c acid, 8-amino-l-naphthol-S-sulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid, S-amino-1-naphth0l-4,6-disulfonic acid, 6-amino-2-naphthalenesulfonic acid, 2-naphthol-8-sulfonic acid, 6-amino-l-naphthalenesulfonic acid, 4,5-dihydroxy-l-naphthalenesulfonic acid, S-amino-1-naphthol-3,5-disulfonic acid, 8-amino-1-naphthol-5,7-disulfonic acid, 2-naphthol-7-sulfonic acid, 4-amino-l-naphthalenesulfonic acid, 1,6-dihydroxy-3-naphthalenesulfonic acid,

and the sodium or potassium salt form of said acids.

Add one molecular proportion H N-XSSO Na wherein X is as above defined.

The composition is then heated slowly to 60-105 C., and preferably to gentle reflux, at which temperature the reactants will be in solution, and held at the foregoing temperature range until the condensation reaction is substantially complete. The condensation reaction will be substantially complete when the composition has been heated at about 60 105 C. for about 12-60 hours.

The composition is cooled to room temperature, preferably with stirring to accelerate the cooling, then cooled externally, such as by means of an ice bath, to -25 C., and enough non-oxidizing mineral acid, such as HCl, H 50 or H PO is added gradually thereto until about pH 3 is reached. During addition of the acid, the composition is maintained at 0-25 C. The pH may be measured on Congo red test paper.

Substantially all S0 gas is then evacuated from the composition at 025 C. The S0 gas may be evacuated by stirring the composition at 025 C., and if desired this may be accelerated by also forcing air through the composition. Substantially all of the S0 gas will have been evacuated or liberated when the easily recognizable S0 odor is no longer detectable.

The resulting precipitated R NHXSSO H product, in acid form, may be collected by filtration, and washed free of mineral acid with 20% aqueous NaCl. If desired, the resulting product may be used as wet press cake, or optionally dried at about 5060 C.

The R NI-IXSSO H may be converted to its corresponding sodium or potassium salt form by stirring the R NHXSSO H in a slight excess of 520% aqueous NaOH, Na CO KOH, or K CO at about 25 C. for about minutes. The product may be collected by slowly evaporating to dryness, or by adding aqueous NaCl to cause precipitation and recovered by filtration.

The following are illustrative examples, in which all parts are by Weight unless otherwise indicated.

EXAMPLE 1 The compound of the formula may be prepared as follows.

Charge 1 liter H O at 40 C. into a 5-liter 3-neck flask. Mix therein by stirring 1,140 gms. NaHSO Add gradually during 30 minutes 119 gms. Na CO Heat to 50 C. Add 361 gms. 7-amino-l-naphthol-S-sulfonic acid. Add thereto 367 gms. sodium S-4-aminophenylthiosulfate. Heat the composition gradually over two hours until it reaches gentle reflux (102105 C.), and hold at gentle reflux for 48 hours. Remove the heat source and stir to room temperature. Cool externally with an ice bath to 10 C. While maintaining 10 C., add 700 gms. 32% aqueous HCl dropwise, resulting in pH 3. Stir 12 hours at 5 -9 C. to permit substantially all S0 gas to be liberated; collect the precipitated product by filtration; wash the product free of mineral acidity by flooding the filter cake on a vacuum filter three times with 20% aqueous NaCl; and optionally dry the resulting moist filter cake at 5060 C. Yield is approximately of theory. Analysis may be conducted by titrating the product with standardized tetrazotized benzidine.

EXAMPLE 2 The compound of the formula may be prepared by adding 150 ml. 5% NaOH to 42.7 gms. of the compound of Example 1, stirring 15 minutes at 25 C., adding gms. 20% aqueous NaCl, and collecting the resulting precipitate by filtration.

EXAMPLE 3 The compound of the formula NaO s HOaSSONH- In the examples given in the following table, the procedure corresponds to that given under Example 1 above, and the examples in the table indicate that 6.68 g. M.W. NaHSO is stirred into one liter H O at 40 C., to which is gradually added 0.74 g. M.W. Na CO and the composition heated to 50 C., whereby a composition buffered at pH 6.2 results. One g. M.W. of the acid in the second column is added, following which 1 g. M.W. of

the thiosulfate in the third column is added. The composition is brought gradually, over a period of about 2 hours, to gentle reflux and there held 12-60 hours, and preferably about 48 hours, until the condensation reaction is substantially complete. The heat source is removed and the composition stirred until it reaches room temperature, following which it is cooled externally to 10 C. While maintaining 10 C., enough 32% aqueous HCl is added to bring the pH to about 3, and the composition is stirred at about 5 C. until substantially all the S0 gas has been liberated. The resulting precipitate is recovered by filtration, washed with 20% aqueous NaCl at 20 C. until free of mineral acid, and dried at 5060 C., resulting in the product of the fourth column. The percent theoretical yield is given in the fifth column. Trivial names of the sulfonic acids in the second column have been used for convenience, and the corresponding systematic names may be found at Lubs, supra, pp. 83, 689-690, and at Venkataraman, The Chemistry of Synthetic Dyes, Academic Press, N.Y.C., vol. 1, p. 171 (1952).

Ex. Percent No. Acid Thiosulfate Product Yield 4;-.. Sacid mN-Qssmm HgSS-C HN OH 63 5 B acid Same as above H21? IIIH SSO H 5 HOaS-@ SOQH 6 Dacid -d0 S0 11 52 7 ss acid .-do HzN NH SSOzH 5o Ember-m 6 S0311 s Dioxy-Iaeid --do HOaS@NH- SSO3H 70 9 Amino G acid H2N- H0 8? E] O H 61 SSOaNa QNH- SOQH 10 Broenners acid Same as above H0 851 803B 11 Dioxy S acid ..do SIO H 63 SSO H 1 12.- F acid do noas- NH 51 l SSO H 13 Naphthlonic acid do Ex. .v No. Add 'lhlomllato mm $1335 on 14... um a,

ad's 50m.

NH BOIH lb.-. Aminol lcld..-... Buneu nbovc 80; 62

NH sod! 1o..... Croeeln mid ..do.. 50,11 ssmn 11.... Km: n 53 an on som 18..... Nnphthlonloicld..........do 80.11 44 19..... I wk! HgNCBgCBgSBOdh 0H 54 no.sscm unmso,n

2o Budd flmuulbova "q aomseca an on 21"... Amino G .014... -.do....-. 80! 51 NH ca so 11 22 Dion Budd ..do..... 801K 0) n ua-{cnQ-ssmn a..... Hm NH cul -seem BL 1 Percent No. Acid, 'rmosuum Product Ymm Kacld sammmmma no NH 01:94:80.1! m

8 He m v 2 Dioxy J acid ..do 0H 7 m 110 NH ca see-H m T '7:

2a-.... Am1n0-7acld am cu,sso,m $0.11 49 soms-{cm3-1n3 50.51 l

27"... Gammaacld Bamounbove 80 H 60 l H0;88-CH; NH

as... I ma .410 on 42 HO|8BOH NH@-S0.H

Bncld .410 so." u

H|N NH CH:880|H o 1 {,4 3 sud mu an on mssom. 110.88 a,

31... B acid Samoa: above BN NH 51 ms s 0.11

31.... Road; ..do EN 0H 57 nmss- Hi BO|H as as ncld d0 43 H;N N

HO H18 3 OH Ex. t No. Add 'rmomum Product x l fia 34.-." Dloxy I laid Bane an Ex. No. 83 62 H|8 NH Ftcid ..d0 51 H0; NH

H35 8 DJ! 80..... Dion 8 old ..do 59 HO NH H 8 8 O H 37..--. D acid ..d0 BOgH 64 38.0 Broenner'u u1d..- ..do 07 H18 8 O|H 39.. AmlnoI do 80d! 7 43 (0..- Guam: lctd Cl OK Cl 74 mN- -ss0,m NHOB m n 1 mid Same u ubovo..-. OH

a..." 8 mid ..do c1 68 Roms-Om: on

43..." Amino G acld..............d0........... Cl 80,1! 7

Amino ma .40.. 50.1: N

no m1 aom 'rn 1o um y Prqfluct J i 4 "5%? 4 0min acid Same am. No. 44.... 801B Clv I 74 Q I V NHGSBOfl-l 46... Dloxylaold "410......" 7 OH 7 25 HOnBB-O-NH on: n... ummma 0cm Q on 11 7 11m Odin NH son! no. V cm 18... I 1.016 flamaulboveflfl... V 74 ao-s NH 0-11 49"... 3.016.... m I I mu NH 80.11 48 so... Duck! -..do r foal a:

a1..." m mmonle an An 7 80m 41 OCH:

m1 ssoa M"... Emma-amid dn Ho's OCH 54 NH seem a na e-mm;

no NH r m 64..." 0:00.11: scld...............do........................-........ BOQI 41 NH-QGBOnH GHQ V 3 C w 88..." !'|cId................. BaN no NH Ex. Percent No. Add Thiosulhte Product Yield 66". Amino 0 acid Some .1 Ex. No. as 30,8 51

omB-uQ-esom 67.. Bmammu mid ..do 55 NH omn-{oHA-Bso-a 68..... Cmooln sold..." ..do 80 42 m: 0.1m on 880.1: m G

Dwld ..do 801B 02 @NHOGOgNH-CH9-BBO.H

l p oo..... seam ..do no no, NH|

NH ;o,NH-cm -sso.a

' 02 61..... Dloxy 8 mld.......... 80|H NH] omn-on. -ssomomn-{cm -ssom 8 51 62 Enid man-bore no NH ONE-{CH 801K ..d 44 63 I said 0 Ho NHQ oma-{cm -esom l-ix. 'i r .\'u. Acid Thtosult'ute Product o4-.. Naphthluniesctd..... Sameas Rx. No. 63 4| OxNH (CH1 50111 g T 65... lucid It will be noted that in the foregoing examples the acid form of the sulfonic acids have been employed as starting materials; however, the corresponding sodium or potassium salt form of said sulionic acids may be substituted therefor to produce the same products produced in the above examples. Also, the end products produced in the above examples are in their acid form, and they may be converted to their sodium or potassium salt form by the method previously described above.

The thiosulfate compounds used in the above examples to prepare the compounds of the present invention may be prepared by known methods as follows. One g. M.W. of 4,4'-diaminodiphcnyldisulfide (U.S. Pat. No. 1,933,217), 3,3'-diaminodiphenyldisulfide (Beil. vol. 13, p. 426), 2,2'-diaminodiphenyldisulfide (Chem. Ab. 28: p. 489?), 4,4'-diamino 2,2 dichlorodiphenyldisulfide (Chem. Ab. 51: p. 16435c), or 4,4-diamino-3,3'-dimethoxydiphenyldisulfide (Chem. Ab. 22: 1965') maybe heated with 4 g. M.W. sodium sulfite, and 3,500 ml.

water at 75' C., while maintaining pH 7-8 with acetic acid, until the reactants are in solution (about 48 hours) to cleave the disulfide molecule between the S atoms' and produce 2 molecules of the corresponding sodium S-2- or -3- or -4-aminophenylthiosulfate, sodium. 8-4-- amino-2-chlorophenylthiosulfate, or sodium S-4-amino- 3-methoxyphenylthiosulfate; and they may be recovered from solution by evaporating to dryness or salting out with NaCl. The following thiosulfate compounds may be produced according to the reference. cited after each one:

H,N+cH,+,sso,Na (Chem. Ab. 47: p. 6860b);

' inmcna sso tsa (Chem. Ab. 48: p. ll48Sc);

(Belgium Patent 644,759).

may be prepared by condensing equimolar amounts m-nitrobenzenesulfonyl chloride and Z-aminoethylthiosutfuric acid. reducing the resulting nitro compound with iron as in U.S. Patent No. 3,151,144, and rendering the result alkaline with a slight excess of NaOH at 25 C.

In the process'of the present invention, the naphthyi radicals of the final products are produced from the sult'onic acids employed herein as follows. B-hydroxy-G- snlt'o-Z-naphthyl is derived from gamma acid, S-hydroxy- 7-sulfo-2-naphthyl is derived from .1 acid or dioxy 1 acid, 8-hyd'roxy-4-sulfo-l-naphthyl is derived from '8 acid or dioxy S acid, 6.8-disulfo-2-naphthyl from amino G acid, 5,7-disulfo-2-naphthyl from amino 1 acid, 8-

l-naphthyl. 8-amino-5,7-disulfo-l-naphthyl, 7-sulfo- Z-naphthyl, 4-sulfo-l-naphthyl, or the sodium or po-. tassium salt form of said naphthyl radicals; X is phenylene, ethylene, propylene,

in which the CH; is bonded to the -SSO;,Z. chlorophenylene in which the C1 is ortho to the -SSO;,Z, methoxyphenylenc in which the methoxy is meta to the SSO Z,

NH CH in which a methylene is bonded to the SSO Z, or

emuc11 in which a methylene is bonded to the SSO Z; and Z is H, Na or K.

. A compound as defined in claim 1, and in which The compound of the formula I mr-Ossom nois- The compound of the formula I 21 5. A method for making a compound of the formula R NHXSSO H, comprising the steps of heating for 12-60 hours at 60105 C. and pH 6.2 an aqueous composition containing approximately equimolar proportions of H NXSSO Na and a member selected from the group consisting of 7-amino-1-naphthol-3-sulfonic acid, 6-arnino-1-naphthol-3-sulfonic acid, S-amino-l-naphthol-S-sulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid, 6-amino-1,3-naphthalenedisulfonic acid, S-amino-1-naphthol-4,6-disulfonic acid, 6-amino-2-naphthalenesulfonic acid, 2-naphthol-8-sulfonic acid, 6-amino-1-naphthalenesulfonic acid, 4,5-dihydroxy-l-naphthalenesulfonic acid, S-amino-1-naphthol-3,5-disulfonic acid, S-amino-1-naphthol-5,7-disulfonic acid, 2-naphthol-7-sulfonic acid, 4-amino-l-naphthalenesulfonic acid,

8-hydroxy-6-sulfo-2-naphthyl,

5 -hydroxy-7 -sulfo-2-naphthyl, 6, 8-disulfo-2-naphthyl,

5 ,7-disulfo-2-naphthyl, 8-amino-4,5-disulfo-l-naphthyl, 6-sulfo-2-naphthyl, 8-sulfo-2-naphthyl, 5-sulfo-2-naphthyl, 8-hydroxy-4,6-disulfo-l-naphthyl, 8-amino-5,7-disulfo-l-naphthyl, 7-sulfo-2-naphthyl, or 4-sulfo-l-naphthyl,

and X is phenylene, ethylene, propylene,

I GE

22 in which the CH is bonded to the divalent S atom of the thiosulfato radical, chlorophenylene in which the C1 is ortho to the divalent S atom of the thiosulfato radical, methoxyphenylene in which the methoxy is meta to the divalent S atom of the thiosulfato radical,

in which a methylene is bonded to the divalent S atom of the thiosulfato radical, or

SOzNH \CH2/z in which a methylene is bonded to the divalent S atom of the thiosulfato radical.

6. A method as defined in claim 5, and further characterized in that R is 8-hydroxy-6-sulfo-2-naphthyl, the sulfonic acid is 7-amino-1-naphthol-3-sulfonic acid, the non-oxidizing mineral acid is HCl, the alkali is about 0.11 molecular proportion Na CO per molecular proportion of NaHSO and in which the heating is at reflux.

7. A method as defined in claim 5, and further characterized in that R is S-hydroxy-7-sulfo-2-naphthyl, the sulfonic acid is 6-amino-1-naphthol-3-sulfonic acid, the non-oxidizing mineral acid is HCl, the alkali is about 0.11 molecular proportion of Na CO per molecular pro portion of NaHSO and in which the heating is at reflux.

References Cited UNITED STATES PATENTS 2,245,971 6/ 1941 Felix et a1. 3,346,587 10/ 1967 Geselbracht. 3,364,247 1/ 1968 Gollis. 3,908,381 10/1968 Westland. 3,913,330 11/1968 Westland.

FOREIGN PATENTS 644,759 7/ 1964 Belgium.

CHARLES B. PARKER, Primary Examiner S. T. LAWRENCE III, Assistant Examiner U.S. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,496,207 February 17, 1970 FrederickE. Barwick" III, et al.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 17, "naphthl" should read naphthyl Column 2, line 54, "naphthl" should read naphthyl Column 6, lines 16 to 22, the left-hand portion of the formula reading should read Columns 9 and 1D, in the table, opposite Ex. 19, second column "H NCH CH SSO Na" should read H NCH CH SSO Na ColumnslS and 16, in the table, opposite EX. 45, fifth column, "74" should read 47 Column 22, line 28, "proportion" should read proportions Signed and sealed this 24th day of November 1970.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents 

